PC cards, also known as data cards or IC cards, are available according to standards of the PCMCIA (Personal Computer Memory Card International Association). Present standards specify that the card is 54 mm wide and 85.6 mm long, and with a 68-contact connector at the front end. Different thicknesses are specified, with the most common card being the Type II card which has a maximum thickness of 5 mm. Extended length PC cards are available, which project rearward of a standard card-receiving slot, with the first 10 mm extension being no thicker or wider than that of a standard PC card.
PC cards in general use have sheet metal covers surrounding a circuit board to prevent components in the card from picking up stray electromagnetic energy. As higher frequency signals are processed, there is increasing problems of cross-talk between different electronic circuit components on the circuit board. It is possible to form grooves in the circuit board around the components and to place an electrically conductive gasket that conforms to the grooves and that is compressed between the circuit board and a metal cover. However, any gasket or other shield must be formed so it can be easily installed. It should be noted that the parts of PC cards are commonly mass produced by a component manufacturer who sells them to smaller card makers. The card maker designs a circuit for a circuit board, forms traces on the board and drill holes in the board, mounts circuit components on the board at the traces, and assembles the parts into a complete card. Any internal electromagnetic shielding should enable the card maker to easily mount the shielding.